South African diesel motorists are facing another painful increase at the pumps tonight, with diesel prices increasing by R3.24 per litre.
With fuel already putting pressure on household, business and fleet budgets, it is understandable that motorists are looking for ways to save.
But there is one shortcut that could end up costing you far more than the price of diesel: putting “dirty” or contaminated diesel into your car.
When diesel prices rise, the temptation for cheaper fuel can be strong. But diesel is not simply diesel. Fuel contaminated with water, dirt, sediment, or other particles can cause serious damage to the fuel system – particularly the injectors and high-pressure fuel pump.
And replacing those components can quickly turn a saving at the pump into a repair bill running into thousands of Rands.
Why is dirty diesel dangerous?
Modern diesel engines operate at extremely high fuel pressures and rely on very precise injector components. The injector has to deliver the correct amount of fuel, at exactly the right time, and in a very fine spray pattern. Contaminated fuel can interfere with that process.
Water, dirt, dust, sediment, and other contaminants can cause wear, corrosion, sticking, and damage to precision components. Vehicle manufacturers warn that contaminated diesel can allow particles into the injection system, potentially causing injectors to stick and, in severe cases, contributing to engine failure.
Water is particularly problematic because diesel also provides lubrication for components within the fuel system. Water can reduce lubrication and contribute to wear and damage.
Once contamination reaches the high-pressure fuel system, the problem can become much bigger than a dirty fuel filter.
Your injectors are precision components – not cheap parts to replace
A diesel injector might look like a relatively small component, but it performs an incredibly important job – it has to deliver fuel in an extremely precise spray pattern. When an injector becomes worn, contaminated, or damaged, the fuel may no longer be delivered correctly.
This can lead to:
- Hard starting
- Rough idling
- Loss of power
- Increased fuel consumption
- Excessive smoke
- Poor acceleration
- Diesel knocking
- Engine warning lights
- Poor combustion
- Increased emissions
Water contamination can cause internal injector components to become damaged or sticky, affecting the injector’s spray pattern and combustion. In severe cases, poor injection can contribute to damage elsewhere in the engine.
And the problem doesn’t necessarily stop with the injectors.
If a high-pressure pump suffers internal wear and starts producing metal particles, those particles can travel through the fuel and into the injectors. That can turn an injector problem into a complete fuel-system problem.
In that situation, simply replacing one injector may not solve the problem. The pump, injectors, rail, and fuel lines may all need to be investigated and cleaned or replaced.
How much can dirty diesel cost you?
This is where trying to save money on fuel can really backfire. The exact cost depends on the vehicle, injector type, extent of the damage, and whether the problem is caught early.
As an indication, new common-rail diesel injectors can cost several thousand Rand each, with some applications costing significantly more. Complete sets on modern diesel vehicles can easily run into tens of thousands of Rands once parts, labour, coding, and related repairs are included.
Suddenly, that cheap tank of fuel doesn’t look quite so cheap.
Don’t ignore the warning signs
If your diesel vehicle suddenly starts behaving differently after filling up, don’t simply keep driving and hope it goes away.
Look out for:
- Hard starting or longer cranking
- Rough idle
- Loss of power
- Excessive smoke
- Increased fuel consumption
- Diesel knock or unusual engine noise
- Engine warning light
These symptoms don’t automatically mean your injectors have failed. Fuel filters, fuel pressure, sensors, wiring, and other components can cause similar symptoms.
That’s why proper testing is important before replacing expensive components.
Prevention is cheaper than replacement
With fuel prices where they are, every litre counts. But protecting your fuel system should be part of the calculation.
Choose your fuel supplier carefully
Use reputable filling stations with good fuel turnover.
Change your fuel filter
Your fuel filter is one of the most important lines of defence between contaminated fuel and your injection system. Don’t neglect scheduled filter replacement, and use a quality filter suitable for your vehicle.
Don’t ignore a water-in-fuel warning
If your vehicle has a water separator or water-in-fuel warning system, take it seriously. Water in diesel can cause significant damage to fuel-system components.
Don’t keep driving when something feels wrong
If problems start immediately or shortly after filling up, have the fuel system checked. Continuing to drive can potentially spread contamination through the system and turn a smaller problem into a much larger one.
And if you think you’ve filled up with bad diesel?
Don’t panic. But don’t ignore it either.
Turbo Diesel Services can help diagnose fuel-system and injector problems and determine what is actually wrong before you start replacing expensive components.
The right approach is to first test, identify the cause and then repair what needs repairing.
Depending on the condition of the injector, the solution may involve cleaning, repair, reconditioning or replacement. The important thing is to identify the cause of the failure – particularly if contaminated fuel is suspected – so that the replacement component doesn’t suffer the same fate.
The bottom line
South Africa’s fuel prices are hurting. That’s a reality for motorists, transport operators, and businesses alike. But when diesel costs more, cutting corners on fuel quality isn’t necessarily a saving. A few Rand saved at the pump is not worth risking a fuel system that could cost tens of thousands of Rand to repair.
Put good fuel in. Maintain your fuel system. And if something goes wrong, get it checked before a small problem becomes a big one.
Got a diesel problem?
If you’re experiencing hard starting, smoke, loss of power, rough running, or suspect fuel contamination, Turbo Diesel Services can help diagnose the problem and get you back on the road.